The control of dimensional change (shrinkage) in blended waxes employed for lost wax casting, also known in the art as investment casting, has traditionally been achieved by the addition of inert, low ash organic fillers to reduce the volume of the formulation subjected to shrinkage. The remainder of the formulation comprises a small number of waxy components, compatible resins, additives and dyes.
It has now been discovered that similar results can be achieved with a lower level of filler, or in some applications without filler, by careful blending of several individual “cuts” of crystalline wax components to achieve control of the dimensional change by influencing the extent, crystal size and type of crystallisation occurring when the “cuts” solidify.